Works not covered by copyright law The underlying idea that is expressed or manifested in the creation of a work generally cannot be the subject of copyright law (see
idea–expression divide). Mathematical formulae will therefore generally form part of the public domain, to the extent that their expression in the form of software is not covered by copyright. Works created before the existence of copyright and patent laws also form part of the public domain. For example,
the Bible and the inventions of
Archimedes are in the public domain. However, translations or new formulations of these works may be copyrighted in themselves.
Expiration of copyright Determination of whether a copyright has expired depends on an examination of the copyright in its source country. In most countries that are signatories to the
Berne Convention, copyright term is based on the life of the author, and extends to 50 or 70 years beyond the death of the author. (See
List of copyright terms of countries.) In the United States, determining whether a work has entered the public domain or is still under copyright depends upon what the law or regulation was at creation, and whether new regulations have grandfathered in certain older works. Because
copyright terms shifted over the course of the 20th century from a fixed-term based on first publication, with
a possible renewal term, to a term extending to 50, then 70, years after the death of the author. The claim that "pre- works are in the public domain" is correct only for published works; unpublished works are under federal copyright for at least the life of the author plus 70 years. Legal traditions differ on whether a work in the public domain can have its copyright restored. In the European Union, the
Copyright Duration Directive was applied retroactively, restoring and extending the terms of copyright on material previously in the public domain. Term extensions by the US and Australia generally have not removed works from the public domain, but rather delayed the addition of works to it. However, the United States moved away from that tradition with the
Uruguay Round Agreements Act, which removed from the public domain many foreign-sourced works that had previously not been in copyright in the US for failure to comply with US-based
formalities requirements. Consequently, in the US, foreign-sourced works and US-sourced works are now treated differently, with foreign-sourced works remaining under copyright regardless of compliance with formalities, while domestically sourced works may be in the public domain if they failed to comply with then-existing formalities requirements—a situation described as odd by some scholars, and unfair by some US-based rightsholders.
Government works , in this case
Abraham Lincoln, are in the public domain. Works of various governments around the world may be excluded from copyright law and may therefore be considered to be in the public domain in their respective countries. They may also be in the public domain in other countries as well. Material in the public domain is still considered so when included as part of larger copyrighted creations. In the United States, work created by the federal government is not subject to copyright law, placing it within the public domain. However, the government may own and use copyrighted materials that were not initially created by them. Alternatively, materials created by the United Kingdom's government are not automatically in public domain but instead placed under the
Open Government Licence. The status of government creations vary depending on the country they are in.
Dedicating works to the public domain Release without copyright notice Before 1 March 1989, in the US, works could be easily given into the public domain by just releasing it without an explicit
copyright notice. With the
Berne Convention Implementation Act of 1988 (and the earlier
Copyright Act of 1976, which went into effect in 1978), all works were by default copyright-protected and needed to be actively given into public domain by a
waiver statement/
anti-copyright can call notice. Not all legal systems have processes for reliably donating works to the public domain, e.g.
civil law of
continental Europe. This may even "effectively prohibit any attempt by copyright owners to surrender rights automatically conferred by law, particularly
moral rights".
Public-domain-like licenses An alternative is for copyright holders to issue a license which irrevocably grants as many rights as possible to the general public. Real public domain makes
licenses unnecessary, as no owner/author is required to grant permission ("
Permission culture"). There are multiple licenses which aim to release works into the public domain. In 2000 the
WTFPL was released as a public domain like
software license. Creative Commons (created in 2002 by
Lawrence Lessig,
Hal Abelson, and
Eric Eldred) has introduced several public-domain-like licenses, called
Creative Commons licenses. These give authors of works (that would qualify for copyright) the ability to decide which protections they would like to place on their material. As copyright is the default license for new material, Creative Commons licenses offer authors a variety of options to designate their work under whichever license they wish, as long as this does not violate standing copyright law. For example, a CC BY license allows for re-users to distribute, remix, adapt, and build upon material, while also agreeing to provide attribution to the author in any of these cases. In 2009 the
Creative Commons released the
CC0, which was created for
compatibility with law domains which have no concept of
dedicating into public domain. This is achieved by a public domain waiver statement and a fallback all-permissive license, in case the waiver is not possible. Unlike in the US, where author's moral rights are generally not specifically regulated, in some countries where moral rights are protected separately in law it is not possible to waive those rights, but only the rights related to the exploitation of the work. A solution to this issue (as found in the Creative Commons Zero dedication) is to interpret the license by setting "three different layers of action. First, the right holder waives any copyright and related rights that can be waived in accordance with the applicable law. Secondly, if there are rights that the right holder cannot waive under applicable law, they are licensed in a way that mirrors as closely as possible the legal effect of a waiver. And finally, if there are any rights that the right holders cannot waive or license, they affirm that they will not exercise them and they will not assert any claim with respect to the use of the work, once again within the limits of applicable law. (...) In countries where moral rights exist but where they can be waived or not asserted, they are waived if asserted (e.g. the UK). In countries where they cannot be waived they will remain into full effect in accordance to the applicable law (think of France, Spain or Italy where moral rights cannot be waived)." The same occurs in Switzerland. The
Unlicense, published around 2010, has a focus on an
anti-copyright message. The Unlicense offers a public domain waiver text with a fallback public domain-like license inspired by permissive licenses but without attribution. Another option is the
Zero Clause BSD license, released in 2006 and aimed at software. In October 2014, the
Open Knowledge Foundation recommends the Creative Commons
CC0 license to dedicate content to the public domain, and the Open Data Commons Public Domain Dedication and License (PDDL) for data. ==Patents==